Formaldehyde hydrosulfite and process of making same.



I the formaldehyde compound oi sodium bihv manufacture o certain Cl:mounds obtained. by the action of aldehyde, on'hydrosulfites,'

sulfite, to which he assigns the formula:

UNITED sTA rns PATENT OFFICE.

EMILE A. RJURNEAUX OF NEW 'EGRK. N. Y, ASSIGNOR TO HERMAN A.

METZ, OF NEW YORK. i. Y.

FORMALDEHYDE HYnRosuLFwe 41%!) PROCESS OF MAKING SAME.

Specification of Letters Patent.

Application filed 'nmh 30,1so5. 3451531 in, 262,865",

Patented Feb. 6, 1966.

To all whom it may oolwern: I 3

Be it known that I, EM LE A. Foumgm 1374, a citizen of the UnitedStates, residing at New'York, in the county of New York end York, haveinvented certain eases of ii eking Same, of which the folhm-ing is aspecification.

In the Unified States Patent No. 769,593

Louis Descam s describe-1 and claims the and more piirtieularly the bodyobtained by the action of formaldehyde on sodium hydro- On December 1,1904, Messrs. IAH'.'BRU- mann, G. Thesmur, and Jos. Frossard pub lisheda ieper in the Revue Germ-ale rles Meiieres 0 om'ntes in which theyprove that the compound described by Mr. Desemnps is not a chemicalindividual, but merely a mechanical mixture in more or less molecularproportions of two bodies: the formaldehyde compound of sodiumbisulfite,

NaHSO UH O i i1 0,

and the body termed by them the formaldell de compound of" sodiumbihydrosulfite, Na. SO CH O+2H Q which result from Bernthsens sodiumhydrosulfite by the following reaction:

Nais20i+2omo+m0= mnsotcnios Nausotonio.

Of these two bodies, which constitute the material eom'mereielly knownas hyraldite or h dresulfite NF, the fornmldehyde sodium ihydrosulfitois the active constituent, whereas the formaldehyde eompmlnd of sodiumbisuhite is merely an unavoidable and undesirable impurity.

The method described by Messrs. Baumenu, Thesmar, and Frossard forproducing drosulfite is so lengthy and onerous us to he of little or nocommercial value.

If it were possible econor'nieally to manufacture the active constituentof hydrosulfite l NF or hymldite in a pure state, free froni theiofnmldellyde compound of sodium liisulfite,

this would constitute {Livery material improvement and progress over thepresent methods, because it )osscsses almost twine the reducing power oithe -zil)m'e-nmne(l hydriiisuliites and is materially more stable, owingto its purity.

To avoid confusion of terms, the salts corresponding to the generalformula M,s,o (Me indicating any univelent metal) heretofore consideredas derived from the hypo theiia: hydrosulfurous acid of Bernthsen, H 8 0are herein termed hydrosullites in m-eordnnce with common usage and thesalts derived from the hy )ot-hetie hydrosulfurous acid ofSehuet-zenlierger, H 89 are hcreinafterreferrcd to as hydrosuliites,(S).

I have found :1 incl hod by which formaldehyde compounds oflgdrosuliites (S) can he prepared eeonomieolly and in a state of greatunity and have also discovered a" new and heretofore unknown basic zinfurlnuldehyde hydrosulfitc (S) which is instrumenlnl in our- I'ying outmyim'ention. This salt separates quentitativcl 1 es :1. whiteerystelline precipitate upon addition of the required umount of asuitable alkaline salt, )refcrnbly sodium carbonate, to a solution 0zinc hydrosullite which has been trentcd with fornialdelwde until'itceases to reduce it solution of indigo sulfonic acid at ordinarytemperature. This new basic zine-salt is characterized by its greatreducing power, one part reducing in the neighbor-howl of one andone-half parts of pure indigo intho form of indigo sulfonii: acid and byits great stability, as it can be dried on the weter imth in the openair without decomposing, which is entirely unprecedented in hydrosulfitecompounds and quite unexpected. The actual composition of lhis eom )oundhas not yet been ascertained with absolute exactness, but it is believedin correspend in the formuln: ZI1S() ll ().ll and to be formed by thefollowingrcip'tion:

eznsgo. +401 120+ NazU0n+til ii )5 2ZnS()2.UlhOJLOi-QNM1503.01MH-( YOQ.

By treating this zine-salt. with e solutlou of sodium carbonate theeorrespondingsoiliuni sslt is formed qunntitetively and can be sepsrutedfrom its solution by ereporation. It appears to be identical with theremarkably stable.

roduct, NaHSO,.CH 0+ 211,0, described yMessrs. Baumann, T 0 mar, andFrossard.

If the basic zinc-salt is treated with an acid, the free acid isliberated and can be used for the preparation of other salts by thewell-known methods. This free acid is also Its solution decomposes onlywhen heated for some time, when sulfurous acid is given off and a yellowoil separates, which becomes crystalline on cooling. The basic zinc-saltmay be prepared by various methods, a satisfactory rocedure beingasfollows: One hundred an twenty parts zinc-dust are pasted up withthree hundred parts boiling water and added to nine hun-. dred partscold water in a lead-lined kettle provided witha stirrer and the amountof sulfurous acid introduced, which is just suflicient to dissolve thetotal amount of zincapproximately two hundred parts. The temperatureduring this whole process should not exceed 45 centigrade. The resultingsolution of zinc hydrosulfite is then cooled to a temperature notexceeding 30 centigrade, filtered to separate it from zinc sulfite andother impurities, and formaldehyde added until the product no longerreduces a solution of indigo sulfonic acid at ordinary temperature. Theamount of formaldehyde reuired is about two hundred and fifty arts. "henadd a highly-concentrated solution of sodium carbonate until the basiczinc-salt is completely preci itated and the mother-liquors, which shoud still be slightly acid to litmus no longer or but very slightly,reduce indigo sulfonlc acid at atemperature exceeding 4. centigrade. Theamount of sodium car. bonate required is about eighty arts. The whitecrystalline precipitate is t en filtered and washed in the usual wayanddried; It can be applied as such for reducing and dis chargingpurposes or for the manufacture of other formaldehyde liydrosulfites (S)in the manner above described.

The formation of this zinc-salt appears to be a secondary reaction.There is at first recipitation of a heavy flocculent white ody, whichsoon decomposes, giving off carbon dioxid and separating the crystallinebasic zinc-salt.

The basic zinc-salt may be prepared by other methods-as, for instance,by reaction of zinc-dust and a suitable acid on sodium bisulfiteformaldehyde under suitable conditions, as described in my co )endingapplication, Serial No. 259,469, filed May 8, 1905.

l. The process of making basic zinc formaldehyde h *drosulfite (S) whichconsists in reacting wit I a suitable alkali compound upon a solution ofzinc hydrosulfite treated with formaldehyde, substantially as described.

2. As a new article of manufacture, basic zinc formaldehyde hydrosulfite(S) occurring as a white crystalline precipitate, capable of being driedon the water-bath in the open air without decomposing, and one )artcapable of reducing about one and one-half parts of pure indigo in theform of indigo sulfonic acid, substantially as described.

3. The process of making alkali formaldehyde hydrosulfitc (S) whichconsists in reacting with a suitable alkali'compound upon the basic zincformaldehyde hydrosulfite (S), substantially as described.

4. Theproeess of making sodium formaldehyde hydrosulfite (S) whlchconsists in reacting with sodium carbonate upon basic zinc formaldehydehydrosulfite (S), substantially as described.

5. The process which consists in reacting with a suitable alkalicompound upon a s o lp tion of zinc hydrosulfite treated with formaldehyde, thereb forming basic zinc formaldehyde h 'drosul ite (S),andithen reacting with a suitable alkali compound upon. said basic zincformaldehyde hydrosulfite (S) to form alkali formaldehyde hydrosulfite(S), substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

EMILE A. FOURNEAUX.

Witnesses H. S. NEIMAN, PAUL LoasER.

